1. Field of the Invention
The invention relates to a clamping device. More particularly, the invention relates to a clamping device disposed on a backlight module.
2. Description of Related Art
In a liquid crystal display (LCD), a cold cathode fluorescent tube (CCFT) or a light emitting diode (LED) is often applied as a light source, and light emitted from the light source passes through a light guide plate and is guided to a display frame. Optical films are required for uniformizing the luminance of the LCD and maintaining the brightness of the entire frame without diminishing the brightness of the light source is not reduced. Currently, the backlight modules mainly adopt optical films (e.g., diffusers) to uniformize and concentrate the light.
However, during a vibration inspection on the backlight module or on the LCD, the optical films are apt to be scratched. Hence, the optical films are often suspended above the light guide plate to prevent movement of the optical films and thereby avoid scratches. Unfortunately, this leads to limited effects in preventing the scratches. On the other hand, in a miniaturized LCD module which employs the LED as the light source, the optical films and the light guide plate are rather close to each other, or the optical film are quite close to one another. Thus, the optical firms are more vulnerable to the scratches.
Given the optical films are firmly fixed, for example, by adhesion or through structural restriction, the optical films are prone to be wavy because of an uneven force received by the optical films. As such, optical performance of the backlight module is deteriorated.